textproduct: Rapid City

KEY MESSAGES

-Blocking pattern will support a large ridge of high pressure over the CONUS this weekend into next week, with very hot temperatures and fire weather concerns

-Thunderstorms will be possible at times this weekend into next week as monsoon impulses advect around the ridge and into the region

-Critical fire weather conditions Sat with high based dry thunderstorms possible along with low RH and dry fuels

DISCUSSION

(This Evening Through Friday) Issued at 1221 PM MDT Fri Jul 24 2026

Upper level ridge over the Rockies will shift east and expand over the central CONUS. This will result in very hot temperatures this weekend into next week. Batches of mid level monsoon moisture will advect through the region as near daily waves eject out of the Rockies and into the FA. Upper level wave and trailing sfc trough now progressing across North Dakota and MT. This system may support a few isolated showers or storms across NW SD in the afternoon, continued a low pop for this. A separate weak impulse may also support a shower or storm across northeast WY in the evening , but the chances for any convection making it into the FA are very slim and have left pops out. Main item of concern will be the large ridge of high pressure that will build into the region. Upper ridge will shift east Sat with very hot temps expected. Highs will reach 100 or higher for most locations on the Plains, supporting adv level heat index readings. Low level moisture will deplete some with mixing, but sustained southerly flow will prevent the BL from drying out too much most places. This will help keep heat index readings higher, esp over central SD. Heat looks to persist most of next week although highs will trend more toward the mid and upper 90s as opposed to the 100s like this weekend. Have issued a heat adv through Sunday when the core of he heat is expected. The adv will be marginal out in northeast WY where very dry BL conds and slightly lower temps will keep heat index values in the 95 to 100 range. In addition to the heat, expect near daily TS chances as monsoon moisture advects around the NW side of the ridge. This includes Sat when a stronger monsoon wave will advect around the ridge in SW flow and into the FA, supporting high based TS chances. Gusty winds will be possible with any thunderstorms in this period given very high based nature and resultant inverted-V profiles per drying BL. Sct wind gusts over 50 mph (likely higher in stronger cells) will be possible give DCAPE of 1500-2000 J/KG. Not much rain expected with these cells, which will support critical fire weather conds when coupled with dry fuels and low RH. Ridge will retrograde back west some by mid next week, supporting slightly cooler but still hot temps, with isold-sct TS chances continuing as the lee trough interacts will passing impulses.

AVIATION

(For the 18Z TAFS Through 18Z Saturday) Issued At 1148 AM MDT Fri Jul 24 2026

VFR conditions are expected through the forecast period.

FIRE WEATHER

Issued At 1221 PM MDT Fri Jul 24 2026

Very hot temperatures return this weekend and will persist into next week as a ridge of high pressure builds over the region. This will support elevated to critical fire weather conditions as RH's drop into the teens on the Plains each day. Winds will be marginal most days, except for perhaps far Western SD Sunday when gusts to 30 will be possible. Poor recovery can also be expected most nights across portions of northeast WY, the Black Hills, and far western SD given warm overnight lows. In addition, there will be near daily chances for isolated thunderstorms as batches of mid level monsoon moisture push through the region. Storms may produce very little rainfall and gusty winds, supporting a dry lightning threat at times. This is especially the case Saturday afternoon and evening across northeast WY and western SD. TS's will produce very little rainfall and gusty/erratic winds. Wind gusts over 50 mph will be possible with any cells, potentially higher. Given high potential for dry TS, min RH's of 15 to 20 percent, very dry fuels, and gusty erratic winds have issued a red flag warning for Sat.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Heat Advisory from noon MDT /1 PM CDT/ Saturday to 8 PM MDT /9 PM CDT/ Sunday for SDZ001-002-012>014-025>027-030>032- 041>044-046-047-049-072>078. Red Flag Warning from noon Saturday to midnight MDT Saturday night for SDZ319>333. WY...Heat Advisory from noon Saturday to 8 PM MDT Sunday for WYZ054>056-058>060. Red Flag Warning from noon Saturday to midnight MDT Saturday night for WYZ314>318.